A drug-drug interaction (DDI) occurs when one medication affects either the pharmacokinetics or pharmacodynamics of another medication. DDIs can result in preventable adverse drug events (ADEs), which can cause harm to patients. A clinical decision support (CDS) system is a health information technology system that assists with clinical decision-making tasks. CDS systems are capable of reducing the frequency of preventable ADEs. However, studies have demonstrated that only around 10% of the alerts fired by CDS systems are applicable in all the circumstances they fire, which can lead to clinician alert fatigue. Alert fatigue occurs when both important and non-important alerts are ignored due to the mental exhaustion and time required to evaluate too many alerts. There is a lack of evidence clearly defining which alerts should fire to clinicians, with the decisions often being made at the institutional level. The primary purpose of this study was to evaluate DDI alerts in an effort to reduce alert fatigue for pharmacists.


This was a prospective performance improvement study conducted within Baptist Health South Florida (BHSF). The primary objective was to identify common DDI alerts that were consistently being overridden by pharmacists. The secondary objectives were to decrease the quantity of clinically insignificant DDI alerts firing to pharmacists and to evaluate alert fatigue experienced by pharmacists during order entry/verification. These objectives were accomplished by using the Lights On Network®, which assisted us with identifying the top 50 DDI alerts in our system. These alerts were then reviewed by the Medication Safety and Clinical Optimization committees at BHSF. Once the final list of DDI alerts that were going to be removed was approved, the pharmacy informatics team turned off these alerts in Cerner. Pre and post-implementation surveys were completed by pharmacists to assess the impact of the implemented changes.


For the month of November 2019, the top 50 DDI alerts accounted for 73,873 out of 161,758 alerts (46%) fired in this month. The most commonly fired DDIs by class included: opioid analgesics with benzodiazepines and opioid analgesics with other opioid analgesics. Of the top 50 DDI alerts, 23 alerts were approved by the Medication Safety and Clinical Optimization committees to be removed. In the month of March 2020, the total number of DDI alerts accounted for 99,329 alerts fired, with the new top 50 accounting for only 23,182 (23%) of the total alerts. The average percentage of DDI alerts overridden decreased from 87% in November to 74% in March (13% decrease). The pre-implementation and post-implementation surveys included a total of 149 responses (94 from the pre-implementation group and 55 from the post-implementation group). The two main changes seen in the survey involved pharmacists’ perception regarding the amount of alerts firing in Cerner and their awareness that BHSF is currently optimizing DDI alerts. Pharmacists expressed no change in their perception of how many alerts they were overriding.


There was a decrease in both the total number of alerts firing and the percentage of overridden alerts after implementation, yet pharmacist perception regarding the amount of alerts being overridden did not seem to change. Further optimization is needed within our healthcare system to decrease alert fatigue. Alerts with high override rates should be evaluated on an ongoing basis to determine whether they are beneficial to the pharmacists or contributing to alert fatigue.

Publication Date


Presented At:

BHSF Pharmacy Residency Conference

Content Type



Jose Ojeda - Pharmacy Resident PGY1

Author Credentials

Jose Ojeda, B.S., Pharm.D.

Kristina Lee, Pharm.D., BCPS

Claudia Chang, Pharm.D., BCPS

Frances Ordieres-Gonzalez, Pharm.D.

Aman Rai, Pharm.D.

Open Access

Available to all.